芽前除草剂种类及浓度对桔梗种子萌发和幼苗生长的影响

Effects of Pre-bud Herbicides and Their Concentrations on Seed Germination and Seedling Growth of Platycodon grandifloras

为筛选适用于桔梗的芽前除草剂,本试验以蒸馏水为对照,研究33%二甲戊灵乳油和720 g/L异丙甲草胺乳油2种除草剂对桔梗种子萌发及幼苗生长的影响。结果表明,与对照相比,720 g/L异丙甲草胺乳油可显著降低桔梗种子发芽率、发芽势和发芽指数,33%二甲戊灵乳油可提高桔梗种子发芽势和发芽指数、降低桔梗种子发芽率。当33%二甲戊灵乳油浓度为0.32 mL/L时,桔梗种子发芽率降低幅度最小。在幼苗生长阶段,33%二甲戊灵乳油和720 g/L异丙甲草胺乳油均可显著降低幼苗根长和苗高,增加根粗和茎粗,其中0.32 mL/L的33%二甲戊灵乳油处理桔梗幼苗苗高和根长的降幅以及幼苗根粗和茎粗的增幅低于其他处理。可见,33%二甲戊灵乳油浓度为0.32 mL/L时对桔梗种子萌发和幼苗生长影响最小。

In order to screen the pre-bud herbicides suitable for Platycodon grandiflorus,this experiment used distilled water as the control to study the effects of two herbicides(33%pendimethalin EC and 720 g/L metolachlor EC)on seed germination and seedling growth of P.grandiflorum.The results showed that compared with the control,720 g/L metolachlor EC could significantly decrease germination rate,germination potential and germination index of P.grandiflorum seeds,while 33%pendimethalin EC could increase germination potential and germination index of P.grandiflorum seeds,and decrease the germination rate of P.grandiflorum seeds.When the concentration of 33%pendimethalin EC was 0.32 mL/L,the decrease in germination rate of P.grandiflorum seeds was the smallest.During the seedling growth stage,both 33%pendimethalin EC and 720 g/L metolachlor EC could significantly reduce the root length and seedling height,and increase the root diameter and stem diameter.Among them,the decrease in seedling height and root length,as well as the increase in root diameter and stem diameter of P.grandiflorum seeds treated with 0.32 mL/L 33%pendimethalin EC were lower than those of other treatments.It can be seen that when the concentration of 33%pendimethalin EC is 0.32 mL/L,the effect on the seed germination and seedling growth of P.grandiflorum is the smallest.